The main additions in "Little Busters! Ecstasy" are 3 heroine routes involving the characters Futaki Kanata, Sasasegawa Sasami and Tokido Saya.
The 3 EX heroines' routes take place of the following:
Saya's route - Before the events of Refrain.
Sasami's route - After the events of Refrain.
Kanata's route - First half of her story is before Refrain and second half is after Refrain.